• December 16, 2012 – 19:59

    Using MRI to Validate Scoring System for Prostate Cancer

    Until recently, wide variations in acquisition protocols and the lack of robust diagnostic criteria make magnetic resonance imaging (MRI) detection of prostate cancer (PCa) one of the most challenging fields in radiology and urology.  A recent trial sought to validate the recently proposed European Society of Urogenital Radiology (ESUR) scoring system for multiparametric MRI (mpMRI) of the prostate, taking advantage of the development of MRI/transrectal ultrasonography (TRUS) fusion technology to evaluate the predictive values of the ESUR scoring system in a cohort of 129 consecutive patients with a total of 1514 cores.

    A prospective study from May to November 2011, 129 consecutive patients with a history of negative TRUS-guided biopsies of the prostate were referred for repeat biopsies. A total of 129 consecutive patients (mean age: 64.7 ± 6.9 yr [range: 47–79]) were enrolled for repeat biopsies (mean number of prior biopsy sessions: 1.3 ± 0.7 [range: 1–4]). Digital rectal examination (DRE) was unremarkable in 107 patients and suspicious in 22 patients (nodule smaller than half a lobe). Mean prostate-specific antigen (PSA) at biopsy was 9.6 ± 5.9 ng/ml (range: 2.7–40.0), and prostate volume (MRI estimate) was 51.1 ± 28.1 cm3 (range: 12–192).  A threshold of ESUR-S (EUR Score Sum) ≥ 9 exhibited the following characteristics: sensitivity: 73.5%; specificity: 81.5%; positive predictive value: 38.2%; negative predictive value: 95.2%; and accuracy: 80.4%.

    Although this trial was not designed to compare repeat biopsy strategies, more targeted cores than random systematic cores were found to be positive for cancer (36.3% compared with 4.9%, p < 0.00001).  Given the inherent challenges of choosing patients for repeat biopsy, the ESUR scoring system was shown to provide clinically relevant stratification of the risk of showing PCa in a given location.  Although the ESUR system was based on literature evidence and consensus, it still lacked validation in a real-life setting.  Only a few cancers were detected solely by random core biopsy specimens, as opposed to the larger yield of cores targeted at mpMRI-suspicious locations.  The validation of the ESUR scoring system and precise targeting of TRUS-guided biopsies now provide convincing leverage in the challenging field of PCa diagnosis.

    Reference: Portalez D, Mozur P, Cornud F, et al.  Validation of the European Society of Urogenital Radiology Scoring System for Prostate Cancer Diagnosis on Multiparametric Magnetic Resonance Imaging in a Cohort of Repeat Biopsy Patients.  Eur J Urol 2012;62:986-996.